We dont need this. We show this message because when the app is opened, there is no filter in 'onmessagereceived' event. For fixing it go to line https://github.com/mozilla-b2g/gaia/blob/master/apps/sms/js/message_manager.js#L66 and put the following line:

`if (message.messageClass === 'class-0') { return;}`

This means that during the SMS App is opened, we are not going to append the message to the UI.